Dynamo-electric machine



NoMoaL L. G. WOOLLEY. Dynamo-Electric Machine.

Patented March 22,1881.

&

F 4 M i N. PETERS. PHOTO'LITHOGRAPHEH, WASHINGTON D Cv UNITED STATES PATENT OFFICE.

LEONIDAS G. WOOLLEY OF MENDON, MICHIGAN.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 239,289, dated March 22, 1881.

Application filed November 26, 1880.

To all whom it may concern:

Be it known that I, LEONIDAS G. WooLLEv, of Mendon, in the county of St. Joseph and State of Michigan, have invented certain new and useful Improvements in DynamoElectric Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being bad to the accoinpanying drawings, which form part of this specification.

My invention relates to an improvement in dynamo electric machines; and it consists in making the armature from a solid ring or band which has a number of grooves cut in its periphery,which grooves extend parallel around its sides.

The object of this part of my invention is to lessen the amount of iron usually employed in making armatures, to enable the armatures to magnetize and demagnetize more quickly, and to entirely do away with the air-passages which have heretofore been used for the purpose of keeping the armature cool, and which air passages cause such a resistance to the armature as it revolves as to require a great amount of power to drive them.

Another part of my invention consists in attaching two semicircular plates at their centers to the poles of a U-shaped magnet or frame and securing to these semicircular plates the magnets which encircle the revolvingarmature, the poles of the U-shaped magnet being wrapped with wire or unwrapped, as may be preferred.

The object of this part of my invention is to cheapen and simplify the construction of the machine, and to give each one of the semicircular plates poles, so as to increase thepower of the magnets.

Figure 1 is an end view of my invention. Fig. 2 is a vertical longitudinal section of the same.

A represents the armature, which is cast in one solid piece, and which, after being turned off in a lathe, both inside and outside, has a number of parallel grooves, B, which extend all around it, cut in its sides. These grooves are so arranged that the surface is divided into thin and thick plates, as shown, the thick ones servin g tolet the dividin g-pins G be passed (No model.)

radially through the armature from the outside. These pins serve to divide the coils of wire, as shown, and, becoming magnetized, bring the poles of the armature as close as possible to the field-of-foreemagnets. These pins are here shown as projecting entirely through the armature, but it is not necessary that they should project entirely through, for if the wire is glued upon that part where it passes through the armature the coils can be kept separate without the use of the pins inside.

It will be seen that the armature is formed from a solid band of soft iron, without any of the air-passages which have heretofore been considered as necessary to keep the armature cool while at work. These air-passages, as the armature revolves, catch a large quantity of air and form such a resistance to the rotation of the armature that a great portion of the power ofthe machine is used up in overcoming this atmospheric resistance alone. These air-passages,1 have discovered, are entirely unnecessary to keep the armature cool, for where grooves are used, as here shown, as fast as the armature becomes heated it heats the air in these grooves, and then this heated air is thrown off by centrifugal force very rapidly as the armature revolves. Heretofore these revolving armatures have been made from a number of plates, which have been bolted or otherwise fastened together, and which are separated from each other by means of washers. These armatures are expensive, troublesome to make, and liable to derangement in many ways, and these defects I entirely overcome by makin my armature of a single solid grooved band. I make my spider G of brass, or some non-magnetic metal, and instead of a flat plate or spider I bend or crook the arms of this hearing, as shown, so as to give them a slight elasticity. When the armature becomes heated and expands the elasticity of the arms caused by the bend or crook which is formed in them prevents any strain upon the fastenings which would tend to loosen or destroy them. This construction of the spider or bearing is of the greatest practical importance,for where the arms are made sufficiently elastic it is impossible for any unequal expansion or contraction of the two parts to cause any trouble in any manner.

The field-of-force magnets are attached to two semicircular plates, I, so as to bring the magnets in close contact with the pins and coils of the armature,which semicircular plates I are secured at their centers to a U-shaped frame, L, which forms, or may not form, a horseshoemagnet. The ends of these semicircular plates I are slightly separated from each other, so as to form a true pole at each end,and thus add very materially to the force of the magnet. Heretofore these magnets have been attached to a ring which entirely encircles the armature; but in using a continuous ring the poles are destroyerhand thus all of their good effects are entirely neutralized. It is to overcome this defect, and to retain the advantages of having the armature encircled by the magnets, as shown, that these semicircular plates are used.

The two uprights are madein a single piece with the base, and the base is made large and heavy enough for the whole machine to rest upon, and thus the construction of the machine will be greatly cheapened and simplified.

The limbs of the U-shaped magnet or frame may not be wound, and thus act simply as a support, and a magnetic conductor suflicient to form a positive pole of one and a negative pole of the other semicircular ring and series of magnets secured thereto.

Having thus described my invention, I claim- 1. In a dynamo-electric machine, an armature made from a solid band or ring and having parallel grooves made around its sides, substantially as shown.

2. In a dynamo-electric machine, a revolving armature made from a single band or ring of iron and having encircling parallel grooves cut in its sides and wound longitudinally with coils of insulated wire, substantially as described.

3. In a dynamo-electric machine, the semicircular plates having the field-of-forcc magnets attached thereto and secured at their centers to the ends of the horseshoe magnet or frame, substantially as described.

at. The combination of the U-shaped frame L, curved plates I, secured to the poles there of, and the field-of-force magnets divided into two groups and secured to the inner sides of the curved plates, the two uprights or poles of the frame being formed in a single piece with the base of the machine, substantially as shown.

In testimony that I claim the foregoing l have hereunto set my hand this 24th day of November, 1880.

LEONIDAS G. WOOLLEY.

Witnesses:

WM. H. KERN, A. G. KISKADDEN. 

